1771 résultats pour "ones"

• Astrobiology - astronomy.

  water to help reactions along. American chemists Stanley Miller and Harold Urey tested part of Oparin and Haldane’s hypothesis in the early 1950s by simulating conditions of the early Earth. In whathas become known as the Miller-Urey experiment, the two scientists connected two flasks with a loop of glass tubing that allowed the gases to pass between the flasks.They filled the upper flask with methane, ammonia, and hydrogen—components thought to have been in the early atmosphere. They filled the...

• Dinosaur - biology.

  The behavior of dinosaurs was governed by their metabolism and by their central nervous system. The dinosaurs’ metabolism—the internal activities that supply thebody’s energy needs—affected their activity level. It is unclear whether dinosaurs were purely endothermic (warm-blooded), like modern mammals, or ectothermic (cold-blooded), like modern reptiles. Endotherms regulate their body temperature internally by means of their metabolism, rather than by using the temperature oftheir surroundin...

• Suicide.

  C Sociological Theories Most social scientists believe that a society’s structure and values can influence suicide rates. French sociologist Émile Durkheim argued that suicide rates are related tosocial integration —that is, the degree to which an individual feels part of a larger group. Durkheim found suicide was more likely when a person lacked social bonds or had relationships disrupted through a sudden change in status, such as unemployment. As one example of the significance of social bond...

• Martin Van Buren.

  political ambitions. The Clintonians cited as one example of Van Buren's unscrupulous methods his support of a convention in 1821 to revise the state's constitution. Van Buren and hisBucktails said they wanted to make the constitution more democratic. The Clintonians retorted that the real aim was to oust them from office. Both sides were right. Therevised constitution introduced a needed extension of voting rights and improved the operation of the state government. However, it also removed many...

• Martin Van Buren

  political ambitions. The Clintonians cited as one example of Van Buren's unscrupulous methods his support of a convention in 1821 to revise the state's constitution. Van Buren and hisBucktails said they wanted to make the constitution more democratic. The Clintonians retorted that the real aim was to oust them from office. Both sides were right. Therevised constitution introduced a needed extension of voting rights and improved the operation of the state government. However, it also removed many...

• Laos - country.

  by the year 2025. About one-quarter of Laos’s people live in mountainous regions. The rest live in upland valleys or on the flood plains of the Mekong and its tributaries.Just over three-quarters of the population live in rural areas, although the proportion of people living in urban areas is steadily increasing. Vientiane is the capital and largest city of Laos. Louangphrabang, the former royal capital, is an increasingly popular tourist destination. Other major cities are theregional capitals...

• Honey Bee - biology.

  B Reproduction and Development The queen controls the sex of her offspring. When an egg passes from her ovary to her oviduct, the queen determines whether the egg is fertilized with sperm from thespermatheca. A fertilized egg develops into a female honey bee, either worker or queen, and an unfertilized egg becomes a male honey bee, or drone. The queen lays the eggs that will develop into more queens in specially constructed downward-pointing, peanut-shaped cells, in which the egg adheres to the...

• Invertebrate - biology.

  animals with a five-pointed design. They live in the sea and move with the help of tiny fluid-filled feet—another feature found nowhere else in the animal world. Zoologists recognize several different groups of worms. The phylum known as flatworms contains the simplest animals possessing heads. Nerves and sense organs areconcentrated in the head. Most flatworms are paper-thin and live in a variety of wet or damp habitats, including the digestive systems of other animals. Roundwormsrepresent anot...

• Invertebrate - biology.

  animals with a five-pointed design. They live in the sea and move with the help of tiny fluid-filled feet—another feature found nowhere else in the animal world. Zoologists recognize several different groups of worms. The phylum known as flatworms contains the simplest animals possessing heads. Nerves and sense organs areconcentrated in the head. Most flatworms are paper-thin and live in a variety of wet or damp habitats, including the digestive systems of other animals. Roundwormsrepresent anot...

• Kuwait (country) - country.

  Oil revenues have allowed Kuwait to build an extensive educational system, yielding a literacy rate of 84 percent. Public school is free and compulsory from the age of 6to 13, and several private schools also teach this age group. Kuwait University (founded in 1966) is also free and offers programs in a wide range of professional andscientific fields at several campuses. Both the extensive library system at Kuwait University and the collection at Kuwait National Museum (1957) were heavily damage...

• William Howard Taft.

  considered him an ideal successor. Because Roosevelt himself was satisfied that Taft's election would ensure that his reform programs were continued, he used hisinfluence with each state's Republican Party to get Taft the nomination. As a result, Taft became the Republican candidate on the first ballot. He was elected president in1908 with a popular vote of 7,675,320 to 6,412,294 for Nebraska editor and Democratic candidate William Jennings Bryan, and an electoral vote of 321 to Bryan's 162.Alth...

• William Howard Taft

  considered him an ideal successor. Because Roosevelt himself was satisfied that Taft's election would ensure that his reform programs were continued, he used hisinfluence with each state's Republican Party to get Taft the nomination. As a result, Taft became the Republican candidate on the first ballot. He was elected president in1908 with a popular vote of 7,675,320 to 6,412,294 for Nebraska editor and Democratic candidate William Jennings Bryan, and an electoral vote of 321 to Bryan's 162.Alth...

• Han Dynasty - History.

  However, these reforms faced serious opposition. The feudal barons formed an alliance and rebelled against Wang Mang. They were joined by members of the Liufamily, who were descended from Jingdi (Ching-ti), a former Han emperor, and a civil war followed. As the empire fell into disorder, militant secret societies formedarmed bands and attacked villages and towns. Wang Mang had believed that proper institutions would eventually bring peace to China, but in AD 23, an army led by the Liu clan brea...

• Costa Rica - country.

  protection from future deforestation is not guaranteed. Deforestation places Costa Rica’s rich biodiversity in danger. The country’s location on the cusp between Northand South America and its abundance of tropical forests make it home to a great variety of species, many of them rare and threatened. Deforestation also contributesto the country’s problematic rate of soil erosion. Costa Rica is party to international treaties concerning biodiversity, climate change ( see Global Warming), endangere...

• Amphibian (animal) - biology.

  strong enough to kill potential predators. C Hearing, Vision, and Vocalizations Amphibians rely on their senses to find food and evade predators. Amphibians lack external ears but have well-developed internal ears. Hearing is most acute in frogs,which typically have a middle ear cavity for transferring sound vibrations from the eardrum, or tympanum, to the inner ear. Frogs and toads also use their keen hearingin communicating with one another. Using a true voice box, or larynx, and a large, exp...

• Brain.

  The hypothalamus lies beneath the thalamus on the midline at the base of the brain. It regulates or is involved directly in the control of many of the body's vital drivesand activities, such as eating, drinking, temperature regulation, sleep, emotional behavior, and sexual activity. It also controls the function of internal body organs bymeans of the autonomic nervous system, interacts closely with the pituitary gland, and helps coordinate activities of the brain stem. D Brain Stem The brain st...

• Spread of Islam - History.

  Muhammad died in 632 and was succeeded by Abu Bakr, the father of Muhammad’s favorite wife, Aisha. Abu Bakr was the first caliph ( khalifah, Arabic for “successor”) of Islam. Like Muhammad, Abu Bakr was a member of the Quraysh clan. While neither Abu Bakr nor any subsequent caliph claimed the role of prophet, they wereleaders of this new religious enterprise that was quickly becoming a political entity as well. The first four caliphs, all of whom were selected by some form of council ofMuslims,...

• Radar.

  gathers the weak returning radar signals and converts them into an electric current. Because a radar antenna may both transmit and receive signals, the duplexerdetermines whether the antenna is connected to the receiver or the transmitter. The receiver determines whether the signal should be reported and often does furtheranalysis before sending the results to the display. The display conveys the results to the human operator through a visual display or an audible signal. B1 The Antenna The rec...

• Segregation in the United States - U.

  acts of discrimination. Writing for the court, Justice Joseph Bradley declared: “When a man has emerged from slavery, and by the aid of beneficent legislation ... theremust be some stage in the progress of his elevation when he takes the rank of a mere citizen, and ceases to be the special favorite of the laws, and when his rights as acitizen, or a man, are to be protected in the ordinary modes by which other men’s rights are protected.” Rather than being the “special favorites” of the law, blac...

• Aksum.

  doctrine that Christ was both divine and human. The Council of Chalcedon condemned Monophysitism in 451, and since that time the Coptic Church has beenindependent of other Christian churches. After the Council of Chalcedon, priests who continued to teach Monophysitism were persecuted in the eastern Roman Empire, and many migrated to Aksum. The influxof priests, along with the support of the royal family, strengthened missionary efforts in Aksum. Many churches and monasteries were founded after 4...

• London (England) - geography.

  D The East End and Docklands The East End, beyond the City of London and the Tower, has long been the home of London’s docks and immigrants. It has frequently been characterized by slums, poverty,and crime. This is the area where the notorious criminal Jack the Ripper prowled. Some portions, such as Bethnal Green, were slums during the Victorian period. Manypoorer immigrants and working-class Londoners still reside in the East End, but its weekend street markets are very popular, especially Pet...

• From Bulfinch's Mythology: Proserpine - anthology.

  the furrow, the seed failed to come up; there was too much sun, there was too much rain; the birds stole the seeds—thistles and brambles were the only growth.Seeing this, the fountain Arethusa interceded for the land. 'Goddess,' said she, 'blame not the land; it opened unwillingly to yield a passage to your daughter. I can tellyou of her fate, for I have seen her. This is not my native country; I came hither from Elis. I was a woodland nymph, and delighted in the chase. They praised mybeauty, bu...

• Jesus Christ I INTRODUCTION Jesus Christ (between 8 and 4 BC-AD 29?

  Monday and Tuesday, according to the synoptists), he drove from the Temple the traders and moneychangers who, by long-established custom, had been allowed totransact business in the outer court (Mark 11:15-19), and he disputed with the chief priests, the scribes, the Pharisees, and the Sadducees questions about hisauthority, tribute to Caesar, and the resurrection. On Tuesday, Jesus also revealed to his disciples the signs that would usher in his Parousia, or second coming. See Second Coming. O...

• Jesus Christ.

  Monday and Tuesday, according to the synoptists), he drove from the Temple the traders and moneychangers who, by long-established custom, had been allowed totransact business in the outer court (Mark 11:15-19), and he disputed with the chief priests, the scribes, the Pharisees, and the Sadducees questions about hisauthority, tribute to Caesar, and the resurrection. On Tuesday, Jesus also revealed to his disciples the signs that would usher in his Parousia, or second coming. See Second Coming. O...

• Jamaica - country.

  majority, the Church of God, Baptists, Anglicans, Seventh-day Adventists, Pentecostalists, and Roman Catholics predominate. Several well-established Jewish, Muslim,and Hindu communities exist. A number of popular sects, such as Pocomania and Rastafarianism, are a significant and famous feature of the national religious life. C Education School attendance by children between the ages of 6 and 11 is nearly universal, and 84 percent of all 12- to 18-year-olds attend secondary institutions. In 2000...

• Indianapolis - geography.

  Amateur athletic competitions are frequent in Indianapolis. Each summer it is the site for the finals of the Hoosier State Games, with athletes of all ages and skill levelscompeting in 21 sports. In 1987 Indianapolis hosted the Tenth Pan American Games, and is often the site for numerous Olympic trials and collegiate sportschampionships. Among the many sports facilities are those for tennis, bicycle racing, skating, and track and field. The city’s professional football team, the Indianapolis Col...

• Radio Astronomy - astronomy.

  equivalent to the apparent angular dimensions of a basketball at the distance of the moon. In 1984, the U.S. government appropriated funds for the construction of aninstallation called the very long baseline array (VLBA), a network of 10 radio antennas spread from the U.S.-Canadian border to Puerto Rico and from Hawaii to the U.S.Atlantic coast. The VLBA is expected to provide angular resolutions in the range of 200-millionths of an arc second. Canada and Australia are both planning similarprogr...

• Latin American Music I INTRODUCTION Tito Puente Playing the Drums Since the 1950s American drummer Tito Puente has popularized Latin American music, especially the mambo, in the United States.

  Panpipe Music of BoliviaWell before the Spanish conquest, native peoples such as the Quechua and Aymara living in the Andes Mountains inBolivia, Peru, and Ecuador, developed a rich musical tradition. Panpipes (set of tuned pipes), made of ceramic, sugarcane,or bone were paired with shell trumpets, cane flutes, and drums, which accompanied dancers during religious and secularceremonies. Large ensembles of 4 to 20 panpipe players are still the norm, and Spanish influences have since beenintegrated...

• Neandertals.

  Neandertals made stone tools by striking flakes from rock “cores.” The cores were carefully selected and prepared so that only a single blow was normally required todetach a flake. A number of relatively standardized flakes were sometimes produced from a single core. These sharp flakes served as “blanks” that were further workedand shaped into the desired tools. Suitable stone was sometimes rare, and often tools were sharpened and resharpened to make new tools, yielding a whole variety ofshapes...

• Neptune (planet) - astronomy.

  The gaseous atmosphere of Neptune contains hydrogen, helium, and about 3 percent methane. It extends about 5,000 km (about 3,000 mi) above the planet’s ocean.Light reflected from Neptune’s deep atmosphere is blue, because the atmospheric methane absorbs red and orange light but scatters blue light. In 1998 astronomersalso identified molecules of methyl in Neptune’s atmosphere. Methyl molecules each contain one carbon atom and three hydrogen atoms. Methyl molecules are knownas hydrocarbon radical...

• Andrew Johnson.

  As senator, Johnson continued to work for a homestead law, and he was disappointed when President James Buchanan vetoed the homestead act of 1860. On theslavery issue, Johnson still followed the orthodox Southern line, but with no great enthusiasm. He voted for the resolutions proposed in 1860 by Senator Jefferson Davisof Mississippi to implement the Dred Scott Decision of 1857, which stated that Congress could not prohibit slavery in the territories of the United States. C1 Presidential Electio...

• Andrew Johnson

  As senator, Johnson continued to work for a homestead law, and he was disappointed when President James Buchanan vetoed the homestead act of 1860. On theslavery issue, Johnson still followed the orthodox Southern line, but with no great enthusiasm. He voted for the resolutions proposed in 1860 by Senator Jefferson Davisof Mississippi to implement the Dred Scott Decision of 1857, which stated that Congress could not prohibit slavery in the territories of the United States. C1 Presidential Electio...

• Conservation.

  cancers, Hodgkin’s disease and leukemia. Unfortunately, human activities have greatly reduced biodiversity around the world. The 20th century encompasses one of the greatest waves of extinction, orelimination of species, to occur on the planet. The greatest threat to biodiversity is loss of habitat as humans develop land for agriculture, grazing livestock, industry,and habitation. The most drastic damage has occurred in the tropical rain forests, which cover less than seven percent of the Earth’...

• Trinidad and Tobago - country.

  III PEOPLE The history of Trinidad and Tobago is reflected in the makeup of its population, among the most ethnically diverse in the Caribbean. Blacks of African ancestry andAsians of Indian ancestry each make up about 40 percent of the population. The remainder is mainly of mixed ancestry, although there are also small groups of peopleof Chinese, European, South American, and Middle Eastern descent. The ethnic diversity of Trinidad and Tobago owes its origins to slavery and its abolition. Afr...

• Tiger - biology.

  have a simple digestive system designed to process meat so that the nutrients can be readily absorbed into the bloodstream. With the exception of white tigers, which have blue eyes, all tigers have yellow eyes. Tigers mainly use vision to find prey. Although tigers see about as well as humansduring the day, their large eye openings gather more light than do human eyes, making tiger night vision far superior to that of humans. In addition, a special structurein the tiger’s eye, called the tapetu...

• Ottoman Empire .

  fleets at Suez, Egypt; though the Portuguese were not expelled, Selim did manage to prevent the establishment of a total Portuguese monopoly over the spice trade. Selim I died in 1520 after having spent most of his short reign on matters pertaining to the east. His son and successor Süleyman I (reigned 1520-1566) again turnedthe attention of the Ottomans to the west. In August 1521 Süleyman, later known as Süleyman the Magnificent, opened the road to Hungary by capturing Belgrade, aHungarian str...

• Ottoman Empire - History.

  fleets at Suez, Egypt; though the Portuguese were not expelled, Selim did manage to prevent the establishment of a total Portuguese monopoly over the spice trade. Selim I died in 1520 after having spent most of his short reign on matters pertaining to the east. His son and successor Süleyman I (reigned 1520-1566) again turnedthe attention of the Ottomans to the west. In August 1521 Süleyman, later known as Süleyman the Magnificent, opened the road to Hungary by capturing Belgrade, aHungarian str...

• Antarctica - Geography.

  The maximum area of sea ice surrounding Antarctica each winter varies from year to year. A marked decline during the 1970s appears to have reversed in more recentdecades, except in the Antarctic Peninsula area. This area has lost almost 40 percent of its sea ice since the start of the 1980s. Sea ice is important to marine life. Krillfeed on algae that live under the sea ice and are released when the ice melts in spring and summer. In turn, many marine animals feed on krill. Emperor penguinsbreed...

• Compositionality

  sentence construction, an operation on meanings, such that the meaning of any sentence is mechanically determined by applying the operations on meanings (given by the rules used in constructing the sentence) to the meanings of the simple parts. (Often a host of extra restrictions are incorporated. For example: the operations may be limited to applying function to argument; the order in which operations are applied may be settled by the structure of the sentence.) Some see such principles as prov...

• Babe Ruth's "Called Shot".

  When Ruth, the second New York batter in the fifth inning, came to the plate, Wrigley Field was roaring. “They called me ‘big belly’ and ‘baboon,’” Ruth recalled,according to the book Great Moments in American Sports by Jerry Brondfield. The New York Times said of the Chicago fans, “It seems decidedly unhealthy for anyone to taunt the great man Ruth too much, and very soon the crowd was to learn its lesson.” During the at bat, Ruth mouthed off to the Chicago players in thedugout as they and...

• US Beats USSR in Hockey.

  The two sides once again exchanged goals during the first period. Sergei Makarov briefly gave the Soviets a lead when he beat Craig. The goal outraged many in thecrowd who felt that referee Karl Kaisla of Finland missed a holding violation by a USSR player in front of the net. Controversy also played a role in the Americans'game-tying goal at the end of the period. With a few seconds left on the clock, Ken Morrow unleashed an 80-foot slap shot that ricocheted to center Mark Johnson,who deposited...

• Messier Lifts the Curse.

  Swept up in the hype, the Rangers came out for game five at the Garden in a virtual sleepwalk. By the start of the third period they were down 3-0. New Yorkscratched back to level the score as Messier culminated the three-goal spurt with a wrist shot midway through the period. Vancouver then stunned the Rangers—andthe sellout crowd—by netting three quick goals to put the game far out of reach. Game six in Vancouver proved even more of a challenge for the Rangers. The team showed little will...

• Malaria.

  last long and is unlikely to be fatal. Infants and children are especially vulnerable to malaria because they have not yet built up immunity to the parasite. Some peoplehave genetic traits that help them resist malaria. Sickle-cell anemia and thalassemia, for example, are inherited blood disorders linked to malaria resistance. Travelers who lack immunity to malaria should take precautionary measures when visiting areas where the disease is prevalent. Such measures include using insectrepellents,...

• Nashville - geography.

  May event has grown into a major festival. In September the city hosts the Tennessee State Fair. One of Nashville's principle attractions is Opryland, a complex of entertainment and broadcasting facilities that offers live music shows, a resort and convention center,and shopping outlets. Since 1974 it has been the home to the Grand Ole Opry radio show, a country-music production that has not missed a broadcast since 1925. Percy Park and Edwin Warner Park provide open space, trails, playing field...

• Surrealism I INTRODUCTION Surrealism, artistic and literary movement that explored and celebrated the realm of dreams and the unconscious mind through the creation of visual art, poetry, and motion pictures.

  Hieronymus Bosch’s The Garden of Earthly Delights (about 1505-1510).© 2008 Salvador Dali, Gala-Salvador Dali Foundation / Artists Rights Society (ARS), New York./Bridgeman Art Library, London/New York Dreams, according to Freud, were the royal road to studying the unconscious, because it is in dreams that our unconscious, primal desires manifest themselves. Theincongruities in dreams, Freud believed, result from a struggle for dominance of ego and id. In attempting to access the real workings of...

• Popular and Social Dance I INTRODUCTION The Cakewalk The cakewalk, a dance of African American origin, was intended to lampoon high-strutting whites at fancy dress balls.

  master. The dance manuals published between 1550 and 1630, written by Thoinot Arbeau of France, Cesare Negri of Italy, and other dancing masters, describe dances such asthe pavane, galliard, allemande, courante, saltarello, and volta, as well as circular branles and progressive longways dances (for a line of couples, in which each couplerepeats the pattern with one new couple after another; see Country Dance). The sense of order and harmony so important during the Renaissance gave rise to forma...

• Antigua and Barbuda - country.

  The monetary unit of Antigua and Barbuda is the East Caribbean (EC) dollar of 100 cents (2.70 East Caribbean dollars equal U.S.$1, a fixed rate since 1976). VI ENVIRONMENTAL CONCERNS The growth of the tourist industry has created some environmental problems, including uncontrolled disposal of sewage from hotels on the beach. Hotel developmentalso threatens the Antiguan mangrove trees. Water management is another major area of concern because of limited natural freshwater resources. Coral reefs...

• From McCulloch v.

  our system shall exist. In discussing these questions, the conflicting powers of the General and State Governments must be brought into view, and the supremacy oftheir respective laws, when they are in opposition, must be settled. If any one proposition could command the universal assent of mankind, we might expect it would be this—that the Government of the Union, though limited in itspowers, is supreme within its sphere of action. This would seem to result necessarily from its nature. It is th...

• Statistics I INTRODUCTION Statistics, branch of mathematics that deals with the collection, organization, and analysis of numerical data and with such problems as experiment design and decision making.

  frequency, column (d), is the ratio of the frequency of an interval to the total count; the relative frequency is multiplied by 100 to obtain the percent relative frequency.The cumulative frequency, column (e), represents the number of students receiving grades equal to or less than the range in each succeeding interval; thus, thenumber of students with grades of 30 or less is obtained by adding the frequencies in column (c) for the first three intervals, which total 53. The cumulative relativef...

• Confucianism.

  IV NEO-CONFUCIANISM After centuries of intellectual and cultural dominance by Buddhism, China began to experience a revival of Confucian thought during the Tang dynasty ( AD 618-907). It was led by poet and essayist Han Yu (Han Yü). Han Yu attacked Buddhism and Daoism, which he believed had kept government officials from seeing how they couldhelp the people. To further public welfare, he urged them to study the way of the ancient sages through the Five Classics . Han Yu almost lost his life f...